1. Field of the Invention
The present invention relates to a retractable safety knife, and more particularly, to a apparatus and method for a surgical retractable safety knife, for both ophthalmic and non-ophthalmic applications, in which a blade is retracted within a handle of the knife.
2. Description of the Related Art
In various surgical procedures, the surgeon typically has to make an incision in the patient to remove unwanted tissue, repair damaged tissue, or implant a device to improve the patient's well being. In certain cases, all three of these activities, or a combination thereof, must be done in a single procedure. For example, in cataract surgery, the surgeon removes a natural, ocular lens that has been clouded by a cataract and replaces it with an artificial lens that will improve the patient's eyesight. To perform this procedure, an incision is made in the cornea using a scalpel. This provides the surgeon with access to the patient's natural lens. The clouded lens is cut loose and removed. There are a number of different procedures used to remove a patient's lens. Two of the more common techniques are known as extracapsular surgery and phacoemulsification.
In extracapsular surgery, the surgeon removes the lens leaving behind the back half of the capsule. In phacoemulsification, the surgeon fragments the lens by ultrasonic vibrations and the lens is simultaneously irrigated and aspirated. After the lens is removed, the surgeon inserts an artificial lens, known as an intraocular lens (IOL), into the eye either behind or in front of the iris. Two C-shaped arms connected to the IOL eventually become scarred into the side of the eye and hold the IOL firmly in place.
In another type of ophthalmic procedure known as the Implantable Contact Lens procedure (ICL), the surgeon makes an incision in the patient's eye and implants a contact lens in the eye in front of the existing lens but behind the iris. This corrects the patient's vision so that he or she can see clearly without the need for external contact lenses or eyeglasses.
Typically a nurse or other surgical assistant manages the devices used during such delicate surgeries. For example, the assistant ensures that the appropriate sterile devices are available in the operating suite for the particular procedure that is to be performed. With respect to scalpels, the nurse often hands the scalpel to the surgeon in a predetermined orientation so that the surgeon can grip the scalpel's handle without taking his or her eyes away from the patient. This also minimizes the possibility that the surgeon may be cut with the blade on the scalpel. After the surgeon completes the incision, the scalpel is handed back to the assistant for proper disposal or sterilization. While the procedure is being performed, this requires the assistant to place the used scalpel on a particular tray that will be removed after the procedure is completed. The devices on the tray are then disposed of or are sterilized for reuse.
If all appropriate protocols are followed, no hospital personnel will be cut by used or unused scalpel blades. Unfortunately, accidental cuts of hospital personnel do occur for a variety of reasons. For example, because the surgeon and assistant are concentrating on the patient and the procedure being performed on the patient, they may not pay close attention to the scalpels. The assistant may put the used scalpels in an inappropriate location or, even if the used scalpels are placed on the proper tray, the blade may be exposed to the operating suite personnel. In these situations, the operating suite personnel may inadvertently come into contact with the blade as they move around the patient during the procedure and be cut or nicked by an exposed blade.
Other hospital personnel may also come into contact with such blades and may also be cut or nicked. Usually, used blades are disposed of in an appropriate sharps container that allows used needles and blades to be inserted into the container but prevents access by hospital personnel to the sharp end of a needle or the sharp cutting surface of the blade. However, during cleanup of the operating suite, the used blades may be exposed prior to their placement in the appropriate sharps container. If hospital personnel are not paying close attention to their activities, or if the exposed blades are hidden from view because they are buried in a pile of other devices or hospital linen, these hospital personnel may come into contact with the sharp cutting surface of the blade and be cut or nicked.
Cuts and nicks from blades are uncomfortable and distracting at best. In addition, such cuts and nicks from used blades may result in blood or body fluid exposure which can result in the spread of infectious diseases between the patient and hospital personnel. Concern over this situation has become especially acute in recent years because of such diseases as acquired immunodeficiency syndrome, i.e. AIDS, and hepatitis. These diseases may be transmitted from an infected person to another person by the transmission of body fluids, typically blood.
Further, the blade of the scalpel must be protected from accidental damage prior to intended use.
In view of the need for a scalpel that can at least minimize the chances of accidental cuts or nicks, while also protecting the cutting edge of the blade, numerous scalpels have been designed. These designs typically take the form of a scalpel having a guard that shields the sharp cutting surface of the blade from undesired contact with hospital personnel and surrounding surfaces. The guard in these devices can be extended to a position shielding the blade or retracted exposing the blade for use. Alternatively, the scalpel may be designed to allow the blade to move into or out of the scalpel handle, to either shield or expose the sharp cutting surface.
These designs, however, may require attention by the user to shield or expose the blade. Additionally, the guard (even when transparent) may visually distort the handle outline when retracted. Any design that allows the blade to move, for retraction or extension purposes, also introduces design issues regarding exact blade positioning and rigidity during use. Such issues also apply in cases in which the user is required to hold the retracted guard as a grip.